XA User Guide 6-96 4/17/98
FCALL Far Call Subroutine Absolute
Syntax: FCALL addr24
Operation: (PC) <-- (PC) + 4
(SP) <-- (SP) - 4
((SP)) <-- (PC)
(PC.23-0) <-- addr24
(PC.0) <-- 0
Description: Causes an unconditional branch to the absolute memory location specified by the
second operand, anywhere in the 16 megabytes XA address space. The 24-bit return address (the
address following the CALL instruction) of the calling routine is saved on the stack. The target
address must be word aligned as CALL or branch will force PC.bit0 to 0.
Note: if the XA is in page 0 mode, only a 16-bit address will be pushed to the stack.
Size: None
Flags Updated: none
Bytes:4
Clocks: 12/8(PZ)
Encoding:
byte 3: lower 8 bits of address (bits 7-0)
byte 4: upper 8 bits of address (bits 23-16)
1 1 0 0 0 1 0 0 address: middle 8 bits (bits 15-8)
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